Comment 0 for bug 1910976

Hi,

I'm asking if it would be possible to cherry-pick patch "dm crypt: add flags to optionally bypass kcryptd workqueues" into the 5.4 Ubuntu kernel. This patch has been merged in mainline kernel 5.9 https://github.com/torvalds/linux/commit/39d42fa96ba1b7d2544db3f8ed5da8fb0d5cb877 but was not tagged for the stable tree.

This patch provides important performance gains for some workloads using dm-crypt / LUKS and cherry-picking it would be very beneficial for dm-crypt users. You can find details on the expected gain in the following links:

* https://www.redhat.com/archives/dm-devel/2020-July/msg00138.html
* https://blog.cloudflare.com/speeding-up-linux-disk-encryption/

The patch mostly applies cleanly on the Ubuntu 5.4 kernel, the only merge conflict is due to the module version at the end of the patch. I can provide a backport patch if needed.

Thanks,